In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external potential.We obtain one-dimensional nonlinear equation which describes the dynamics of transverse...In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external potential.We obtain one-dimensional nonlinear equation which describes the dynamics of transversetight confined bosonic gas from three-dimension to one-dimension,and find one-dimensional s-wave scattering lengthwhich depends on the shape of transverse confining potential.If the funnel trapping potential is strong enough at zerotemperature,all transverse excitations are frozen.We find the dynamic equation which describes the Tonks-Girardeaugas and present a qualitative analysis of the experimental accessibility of the Tonks-Girardeau gas with funnel-trappedalkalic atoms.展开更多
Chinese-American literature that grew up at the end of 1960s and the beginning of 1970s not only increased in quantity but also broke through in theme and genre. From 1970s, Chinese-American literature has developed b...Chinese-American literature that grew up at the end of 1960s and the beginning of 1970s not only increased in quantity but also broke through in theme and genre. From 1970s, Chinese-American literature has developed by leaps and bounds and a group of outstanding and innovative writers also appeared who earned the respect of literary critics and enjoyed a large number of American readers--for example, Maxine Hong Kingston （1940-） and Amy Tan （1952-） as novelists and David Henry Hwang （1957-） as a playwright. The woman warrior in particular is regarded as the work that marks the rise of Chinese-American literature in modem American literary history. This paper intends to argue the investigation of individual identity of Maxine Hong Kingston as a Chinese-American woman and the deliberate misinterpretation of Chinese traditions in The woman warrior. In addition, to create the collective identity of Chinese-Americans, the author actually takes the way of traditional Chinese movies that she has inherited and uses the highlights which are most appreciated by the Westerners to cater to their interests and fantasies.展开更多
BeiDou Global Navigation Satellite System(BDS-3)not only performs the normal positioning,navigation and timing(PNT)functions,but also provides featured services,which are divided into geostationary orbit(GEO)and mediu...BeiDou Global Navigation Satellite System(BDS-3)not only performs the normal positioning,navigation and timing(PNT)functions,but also provides featured services,which are divided into geostationary orbit(GEO)and medium earth orbit(MEO)satellite-based featured services in this paper.The former refers to regional services consisting of the regional short message communication service(RSMCS),the radio determination satellite service(RDSS),the BDS satellite-based augmented service(BDSBAS)and the satellite-based precise point positioning service via B2b signal(B2b-PPP).The latter refers to global services consisting of the global short message communication service(GSMCS)and the MEO satellite-based search and rescue(MEOSAR)service.The focus of this paper is to describe these featured services and evaluate their performances.The results show that the inter-satellite link(ISL)contributes a lot to the accuracy improvement of orbit determination and time synchronization for the whole constellation.Compared with some other final products,the root mean squares(RMS)of the BDS-3 precise orbits and broadcast clock are 25.1 cm and 2.01 ns,respectively.The positioning accuracy of single frequency is better than 6 m,and that of the generalized RDSS is usually better than 12 m.For featured services,the success rates of RSMCS and GSMCS are better than 99.9% and 95.6%,respectively;the positioning accuracies of single and dual frequency BDSBAS are better than 3 and 2 m,respectively;the positioning accuracy of B2b-PPP is better than 0.6 m,and the convergence time is usually smaller than 30 min;the single station test shows that the success rate of MEOSAR is better than 99%.Due to the ISL realization in the BDS-3 constellation,the performance and capacities of the global featured services are improved significantly.展开更多
Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement （RCD）. Additionally, selection against interspecific fighting can cause aggressi...Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement （RCD）. Additionally, selection against interspecific fighting can cause aggressive traits to diverge between sympatric species via agonistic character displacement （ACD）. By directly affecting conspecific recognition traits, RCD and ACD between species can also incidentally cause divergence in mating and fighting traits among populations within a species [termed cascade RCD （CRCD） and cascade ACD]. Here, we demonstrate patterns consistent with male-driven RCD and ACD in 2 groups of darters （orangethroat darter clade Ceasia and rainbow darter Etheostoma caeruleum）. In both groups, males that occur in sympatry （between Ceasia and E. caeruleum） have higher levels of preference for mating and fighting with conspecifics over heterospecifics than do males from allopatry. This is consistent with RCD and ACD. We also found patterns consistent with CRCD and cascade ACD among species of Ceasia. Ceasia males that are sympatric to E. caeruleum （but allopatric to one another） also have heightened preferences for mat- ing and fighting with conspecific versus heterospecific Ceasia. In contrast, Ceasia males that are allopatric to E. caeruleum readily mate and fight with heterospecific Ceasia. We suggest that RCD and ACD between Ceasia and E. caeruleum has incidentally led to divergence in mating and fighting traits among Ceasia species. This study is unique in that male preferences evolve via both RCD （male preference for conspecific females） and ACD （male preference to fight conspecific males） which leads to subsequent divergence among allopatric lineages.展开更多
BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satel...BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satellites in Inclined Geosynchronous Orbit （IGSO）, and 4 satellites in Medium Earth Orbit （MEO）. In this paper, its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing, including satellite visibility, Position Dilution of Precision （PDOP） value, the precision of code and carrier phase measurements, the accuracy of single point positioning and differential position- ing and ambiguity resolution （AR） performance, which are also compared with those of GPS. It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm, respectively, which are comparable to those of GPS, and the accuracy of BDS single point positioning has satisfied the design requirement. The real-time kinematic positioning is also feasible by BDS alolae in the opening condition, since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS. The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km, which is on the same level with that of GPS. For the combined BDS and GPS, the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly. The accu- racy of BDS/GPS carrier phase differential positioning is about 35 and 20 % better than that of GPS for two short baseline tests in this study. The accuracy of BDS code differential positioning is better than 2.5 m. However it is worse than that of GPS, which may result from large code multipath errors of BDS GEO satellite measurements.展开更多
Aggression is a common behavioral strategy employed by animals to secure limited resources, but must be applied with restraint to limit potential costs including injury. How animals make the adap- tive decision to fig...Aggression is a common behavioral strategy employed by animals to secure limited resources, but must be applied with restraint to limit potential costs including injury. How animals make the adap- tive decision to fight or flee is barely known. Here, we review our work on crickets that reveals the roles of biogenic amines, primarily octopamine （the insect analog of noradrenaline） and nitric oxide （NO）. Using aminergic drugs, we found that amines are not essential for actually initiating aggres- sion. However, octopamine is necessary for mediating the aggression-promoting effects of poten- tially rewarding experiences including stimulation with a male antenna, physical exertion, winning, and resource possession. Hence, octopamine can be considered as the motivational component of aggression. Imposed handicaps that impede aggressive signaling revealed that the agonistic actions of an opponent perceived during fighting act to reduce aggression, and that crickets make the deci- sion to flee the moment the accumulated sum of such aversive experiences exceeds some critical level. Treatment with nitridergic drugs revealed that the impact of the opponent＇s aggressive actions is mediated by NO. NO acts to suppress aggression by promoting the tendency to flee and is primarily responsible for the depressed aggressiveness of subordinates after social defeat. Octopamine and dopamine can each restore aggression in subordinates, but only dopamine is necessary for normal recovery. The role of serotonin remains unclear, and is discussed. We conclude that octopamine and NO control the decision to fight or flee by mediating the effects of potentially rewarding and aversive experiences, respectively.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.10647144Natural Science Foundation under Grant GK0513102Doctoral Special Fund of Yangzhou University
文摘In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external potential.We obtain one-dimensional nonlinear equation which describes the dynamics of transversetight confined bosonic gas from three-dimension to one-dimension,and find one-dimensional s-wave scattering lengthwhich depends on the shape of transverse confining potential.If the funnel trapping potential is strong enough at zerotemperature,all transverse excitations are frozen.We find the dynamic equation which describes the Tonks-Girardeaugas and present a qualitative analysis of the experimental accessibility of the Tonks-Girardeau gas with funnel-trappedalkalic atoms.
文摘Chinese-American literature that grew up at the end of 1960s and the beginning of 1970s not only increased in quantity but also broke through in theme and genre. From 1970s, Chinese-American literature has developed by leaps and bounds and a group of outstanding and innovative writers also appeared who earned the respect of literary critics and enjoyed a large number of American readers--for example, Maxine Hong Kingston （1940-） and Amy Tan （1952-） as novelists and David Henry Hwang （1957-） as a playwright. The woman warrior in particular is regarded as the work that marks the rise of Chinese-American literature in modem American literary history. This paper intends to argue the investigation of individual identity of Maxine Hong Kingston as a Chinese-American woman and the deliberate misinterpretation of Chinese traditions in The woman warrior. In addition, to create the collective identity of Chinese-Americans, the author actually takes the way of traditional Chinese movies that she has inherited and uses the highlights which are most appreciated by the Westerners to cater to their interests and fantasies.
基金supported by the National Natural Science Foundation of China(41931076,L1924033,and 41904042)National Key Research and Development Program of China(2020YFB0505800)。
文摘BeiDou Global Navigation Satellite System(BDS-3)not only performs the normal positioning,navigation and timing(PNT)functions,but also provides featured services,which are divided into geostationary orbit(GEO)and medium earth orbit(MEO)satellite-based featured services in this paper.The former refers to regional services consisting of the regional short message communication service(RSMCS),the radio determination satellite service(RDSS),the BDS satellite-based augmented service(BDSBAS)and the satellite-based precise point positioning service via B2b signal(B2b-PPP).The latter refers to global services consisting of the global short message communication service(GSMCS)and the MEO satellite-based search and rescue(MEOSAR)service.The focus of this paper is to describe these featured services and evaluate their performances.The results show that the inter-satellite link(ISL)contributes a lot to the accuracy improvement of orbit determination and time synchronization for the whole constellation.Compared with some other final products,the root mean squares(RMS)of the BDS-3 precise orbits and broadcast clock are 25.1 cm and 2.01 ns,respectively.The positioning accuracy of single frequency is better than 6 m,and that of the generalized RDSS is usually better than 12 m.For featured services,the success rates of RSMCS and GSMCS are better than 99.9% and 95.6%,respectively;the positioning accuracies of single and dual frequency BDSBAS are better than 3 and 2 m,respectively;the positioning accuracy of B2b-PPP is better than 0.6 m,and the convergence time is usually smaller than 30 min;the single station test shows that the success rate of MEOSAR is better than 99%.Due to the ISL realization in the BDS-3 constellation,the performance and capacities of the global featured services are improved significantly.
基金This work was supported by the Cooperative State Research, Education, and Extension Service, US Department of Agriculture, under project number ILLU 875-952, the National Science Foundation （DEB 0953716 and IOS 1701676）, and the University of IlLinois. The treatment of animals was approved by the Institutional Animal Care and Use Committee under protocol No. 14097.
文摘Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement （RCD）. Additionally, selection against interspecific fighting can cause aggressive traits to diverge between sympatric species via agonistic character displacement （ACD）. By directly affecting conspecific recognition traits, RCD and ACD between species can also incidentally cause divergence in mating and fighting traits among populations within a species [termed cascade RCD （CRCD） and cascade ACD]. Here, we demonstrate patterns consistent with male-driven RCD and ACD in 2 groups of darters （orangethroat darter clade Ceasia and rainbow darter Etheostoma caeruleum）. In both groups, males that occur in sympatry （between Ceasia and E. caeruleum） have higher levels of preference for mating and fighting with conspecifics over heterospecifics than do males from allopatry. This is consistent with RCD and ACD. We also found patterns consistent with CRCD and cascade ACD among species of Ceasia. Ceasia males that are sympatric to E. caeruleum （but allopatric to one another） also have heightened preferences for mat- ing and fighting with conspecific versus heterospecific Ceasia. In contrast, Ceasia males that are allopatric to E. caeruleum readily mate and fight with heterospecific Ceasia. We suggest that RCD and ACD between Ceasia and E. caeruleum has incidentally led to divergence in mating and fighting traits among Ceasia species. This study is unique in that male preferences evolve via both RCD （male preference for conspecific females） and ACD （male preference to fight conspecific males） which leads to subsequent divergence among allopatric lineages.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.41020144004,41374019,41104022)the National High Technology Research and Development Program of China(Grant No.2013AA122501)
文摘BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satellites in Inclined Geosynchronous Orbit （IGSO）, and 4 satellites in Medium Earth Orbit （MEO）. In this paper, its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing, including satellite visibility, Position Dilution of Precision （PDOP） value, the precision of code and carrier phase measurements, the accuracy of single point positioning and differential position- ing and ambiguity resolution （AR） performance, which are also compared with those of GPS. It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm, respectively, which are comparable to those of GPS, and the accuracy of BDS single point positioning has satisfied the design requirement. The real-time kinematic positioning is also feasible by BDS alolae in the opening condition, since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS. The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km, which is on the same level with that of GPS. For the combined BDS and GPS, the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly. The accu- racy of BDS/GPS carrier phase differential positioning is about 35 and 20 % better than that of GPS for two short baseline tests in this study. The accuracy of BDS code differential positioning is better than 2.5 m. However it is worse than that of GPS, which may result from large code multipath errors of BDS GEO satellite measurements.
文摘Aggression is a common behavioral strategy employed by animals to secure limited resources, but must be applied with restraint to limit potential costs including injury. How animals make the adap- tive decision to fight or flee is barely known. Here, we review our work on crickets that reveals the roles of biogenic amines, primarily octopamine （the insect analog of noradrenaline） and nitric oxide （NO）. Using aminergic drugs, we found that amines are not essential for actually initiating aggres- sion. However, octopamine is necessary for mediating the aggression-promoting effects of poten- tially rewarding experiences including stimulation with a male antenna, physical exertion, winning, and resource possession. Hence, octopamine can be considered as the motivational component of aggression. Imposed handicaps that impede aggressive signaling revealed that the agonistic actions of an opponent perceived during fighting act to reduce aggression, and that crickets make the deci- sion to flee the moment the accumulated sum of such aversive experiences exceeds some critical level. Treatment with nitridergic drugs revealed that the impact of the opponent＇s aggressive actions is mediated by NO. NO acts to suppress aggression by promoting the tendency to flee and is primarily responsible for the depressed aggressiveness of subordinates after social defeat. Octopamine and dopamine can each restore aggression in subordinates, but only dopamine is necessary for normal recovery. The role of serotonin remains unclear, and is discussed. We conclude that octopamine and NO control the decision to fight or flee by mediating the effects of potentially rewarding and aversive experiences, respectively.
